CombinedBlockCache (Apache HBase 1.4.11 API)

java.lang.Object
- org.apache.hadoop.hbase.io.hfile.CombinedBlockCache

All Implemented Interfaces:

Iterable<CachedBlock>, HeapSize, BlockCache, ResizableBlockCache

Direct Known Subclasses:

InclusiveCombinedBlockCache
```
@InterfaceAudience.Private
public class CombinedBlockCache
extends Object
implements ResizableBlockCache, HeapSize
```
CombinedBlockCache is an abstraction layer that combines LruBlockCache and BucketCache. The smaller lruCache is used to cache bloom blocks and index blocks. The larger l2Cache is used to cache data blocks. getBlock(BlockCacheKey, boolean, boolean, boolean) reads first from the smaller lruCache before looking for the block in the l2Cache. Blocks evicted from lruCache are put into the bucket cache. Metrics are the combined size and hits and misses of both caches.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class CombinedBlockCache.CombinedCacheStats

Nested Classes
Modifier and Type	Class and Description
`static class`	`CombinedBlockCache.CombinedCacheStats`

Field Summary

Fields
Modifier and Type Field and Description

protected CombinedBlockCache.CombinedCacheStats combinedCacheStats

protected BlockCache l2Cache

protected LruBlockCache lruCache

Fields
Modifier and Type	Field and Description
`protected CombinedBlockCache.CombinedCacheStats`	`combinedCacheStats`
`protected BlockCache`	`l2Cache`
`protected LruBlockCache`	`lruCache`

Constructor Summary

Constructors
Constructor and Description

CombinedBlockCache(LruBlockCache lruCache, BlockCache l2Cache)

Constructors
Constructor and Description
`CombinedBlockCache(LruBlockCache lruCache, BlockCache l2Cache)`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`cacheBlock(BlockCacheKey cacheKey, Cacheable buf)` Add block to cache (defaults to not in-memory).
`void`	`cacheBlock(BlockCacheKey cacheKey, Cacheable buf, boolean inMemory, boolean cacheDataInL1)` Add block to cache.
`boolean`	`evictBlock(BlockCacheKey cacheKey)` Evict block from cache.
`int`	`evictBlocksByHfileName(String hfileName)` Evicts all blocks for the given HFile.
`Cacheable`	`getBlock(BlockCacheKey cacheKey, boolean caching, boolean repeat, boolean updateCacheMetrics)` Fetch block from cache.
`BlockCache[]`	`getBlockCaches()`
`long`	`getBlockCount()` Returns the number of blocks currently cached in the block cache.
`long`	`getCurrentDataSize()` Returns the occupied size of data blocks, in bytes.
`long`	`getCurrentSize()` Returns the occupied size of the block cache, in bytes.
`long`	`getDataBlockCount()` Returns the number of data blocks currently cached in the block cache.
`long`	`getFreeSize()` Returns the free size of the block cache, in bytes.
`long`	`getMaxSize()` Returns the Max size of the block cache, in bytes.
`CacheStats`	`getStats()` Get the statistics for this block cache.
`long`	`heapSize()`
`Iterator<CachedBlock>`	`iterator()`
`void`	`setMaxSize(long size)` Sets the max heap size that can be used by the BlockCache.
`void`	`shutdown()` Shutdown the cache.
`long`	`size()` Returns the total size of the block cache, in bytes.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - lruCache
```
protected final LruBlockCache lruCache
```
  - l2Cache
```
protected final BlockCache l2Cache
```
  - combinedCacheStats
```
protected final CombinedBlockCache.CombinedCacheStats combinedCacheStats
```
- Constructor Detail
  - CombinedBlockCache
```
public CombinedBlockCache(LruBlockCache lruCache,
                  BlockCache l2Cache)
```
- Method Detail
  - heapSize
```
public long heapSize()
```
    Specified by:
    
    heapSize in interface HeapSize
    
    Returns:
    Approximate 'exclusive deep size' of implementing object. Includes count of payload and hosting object sizings.
  - cacheBlock
```
public void cacheBlock(BlockCacheKey cacheKey,
              Cacheable buf,
              boolean inMemory,
              boolean cacheDataInL1)
```
    Description copied from interface: BlockCache
    
    Add block to cache.
    
    Specified by:
    
    cacheBlock in interface BlockCache
    
    Parameters:
    cacheKey - The block's cache key.
    buf - The block contents wrapped in a ByteBuffer.
    inMemory - Whether block should be treated as in-memory
    cacheDataInL1 - If multi-tier block cache deploy -- i.e. has an L1 and L2 tier -- then if this flag is true, cache data blocks up in the L1 tier (meta blocks are probably being cached in L1 already).
  - cacheBlock
```
public void cacheBlock(BlockCacheKey cacheKey,
              Cacheable buf)
```
    Description copied from interface: BlockCache
    
    Add block to cache (defaults to not in-memory).
    
    Specified by:
    
    cacheBlock in interface BlockCache
    
    Parameters:
    cacheKey - The block's cache key.
    buf - The object to cache.
  - getBlock
```
public Cacheable getBlock(BlockCacheKey cacheKey,
                 boolean caching,
                 boolean repeat,
                 boolean updateCacheMetrics)
```
    Description copied from interface: BlockCache
    
    Fetch block from cache.
    
    Specified by:
    
    getBlock in interface BlockCache
    
    Parameters:
    cacheKey - Block to fetch.
    caching - Whether this request has caching enabled (used for stats)
    repeat - Whether this is a repeat lookup for the same block (used to avoid double counting cache misses when doing double-check locking)
    updateCacheMetrics - Whether to update cache metrics or not
    
    Returns:
    Block or null if block is not in 2 cache.
  - evictBlock
```
public boolean evictBlock(BlockCacheKey cacheKey)
```
    Description copied from interface: BlockCache
    
    Evict block from cache.
    
    Specified by:
    
    evictBlock in interface BlockCache
    
    Parameters:
    cacheKey - Block to evict
    
    Returns:
    true if block existed and was evicted, false if not
  - evictBlocksByHfileName
```
public int evictBlocksByHfileName(String hfileName)
```
    Description copied from interface: BlockCache
    
    Evicts all blocks for the given HFile.
    
    Specified by:
    
    evictBlocksByHfileName in interface BlockCache
    
    Returns:
    the number of blocks evicted
  - getStats
```
public CacheStats getStats()
```
    Description copied from interface: BlockCache
    
    Get the statistics for this block cache.
    
    Specified by:
    
    getStats in interface BlockCache
    
    Returns:
    Stats
  - shutdown
```
public void shutdown()
```
    Description copied from interface: BlockCache
    
    Shutdown the cache.
    
    Specified by:
    
    shutdown in interface BlockCache
  - size
```
public long size()
```
    Description copied from interface: BlockCache
    
    Returns the total size of the block cache, in bytes.
    
    Specified by:
    
    size in interface BlockCache
    
    Returns:
    size of cache, in bytes
  - getMaxSize
```
public long getMaxSize()
```
    Description copied from interface: BlockCache
    
    Returns the Max size of the block cache, in bytes.
    
    Specified by:
    
    getMaxSize in interface BlockCache
    
    Returns:
    size of cache, in bytes
  - getFreeSize
```
public long getFreeSize()
```
    Description copied from interface: BlockCache
    
    Returns the free size of the block cache, in bytes.
    
    Specified by:
    
    getFreeSize in interface BlockCache
    
    Returns:
    free space in cache, in bytes
  - getCurrentSize
```
public long getCurrentSize()
```
    Description copied from interface: BlockCache
    
    Returns the occupied size of the block cache, in bytes.
    
    Specified by:
    
    getCurrentSize in interface BlockCache
    
    Returns:
    occupied space in cache, in bytes
  - getCurrentDataSize
```
public long getCurrentDataSize()
```
    Description copied from interface: BlockCache
    
    Returns the occupied size of data blocks, in bytes.
    
    Specified by:
    
    getCurrentDataSize in interface BlockCache
    
    Returns:
    occupied space in cache, in bytes
  - getBlockCount
```
public long getBlockCount()
```
    Description copied from interface: BlockCache
    
    Returns the number of blocks currently cached in the block cache.
    
    Specified by:
    
    getBlockCount in interface BlockCache
    
    Returns:
    number of blocks in the cache
  - getDataBlockCount
```
public long getDataBlockCount()
```
    Description copied from interface: BlockCache
    
    Returns the number of data blocks currently cached in the block cache.
    
    Specified by:
    
    getDataBlockCount in interface BlockCache
    
    Returns:
    number of blocks in the cache
  - iterator
```
public Iterator<CachedBlock> iterator()
```
    Specified by:
    
    iterator in interface Iterable<CachedBlock>
    
    Specified by:
    
    iterator in interface BlockCache
    
    Returns:
    Iterator over the blocks in the cache.
  - getBlockCaches
```
public BlockCache[] getBlockCaches()
```
    Specified by:
    
    getBlockCaches in interface BlockCache
    
    Returns:
    The list of sub blockcaches that make up this one; returns null if no sub caches.
  - setMaxSize
```
public void setMaxSize(long size)
```
    Description copied from interface: ResizableBlockCache
    
    Sets the max heap size that can be used by the BlockCache.
    
    Specified by:
    
    setMaxSize in interface ResizableBlockCache
    
    Parameters:
    size - The max heap size.

Class CombinedBlockCache

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

lruCache

l2Cache

combinedCacheStats

Constructor Detail

CombinedBlockCache

Method Detail

heapSize

cacheBlock

cacheBlock

getBlock

evictBlock

evictBlocksByHfileName

getStats

shutdown

size

getMaxSize

getFreeSize

getCurrentSize

getCurrentDataSize

getBlockCount

getDataBlockCount

iterator

getBlockCaches

setMaxSize